cc: Etiquette

When is it proper to cc: and when is it considered tacky, or even rude? 

I think if you are announcing something like an event it is okay to cc: because it's just like sending an invitation or a flyer.  You wouldn't personalize each of these so you don't need to personalize the email. 

However, if you are planning a small get together, or a camping trip or something for a small group of people I think it is tacky to send a cc: list email saying "Want to go camping this weekend?"  Take 5 extra minutes and just send them separately.  Seriously, it sends the message: "My time is too valuable to write to you personally but if you'd like to show up and spent time as part of my entourage you are encouraged to do so.  I may or may not converse with you, sign autographs, or remember your name."

Is it rude to send a cc:'d email to your closest friends announcing a major life change, such as moving across the country?  How about engagement or pregnancy announcements?  My unsolicited advice is:  If you call someone your friend, don't cc: them on major life events.  And if you don't call someone your friend, why are you emailing them about it in the first place?  I think a cc: email from a friend regarding something big says, "I don't really care what you think, just send me a gift/I feel obligated to update you on my very exciting life."